The present invention disclosed herein relates to photochromic glass, and more particularly, to photochromic glass switched due to the selective irradiation of light.
Most of functional windows used today use an electro-chromic device having a transmittance varying depending on an applied voltage. Since a general electro-chromic device uses electrolyte, there are limitations in that it is difficult to apply to windows and doors and in stability and response time. Thus, when light having a particular wavelength is irradiated, a change in a molecular structure occurs and thus there is a need to develop a photochromic device showing a characteristic that the transmittance of a visible light decreases. A photochromic layer for the photochromic device is an organic material and causes a photochromic phenomenon in reaction to an ultraviolet ray. Also, an organic dye is being developed which ensures stability at room temperature and thus maintains a photochromic state before light having another wavelength is applied.